Current through Register Vol. 54, No. 23, June 8, 2024
Section 73.54 - Subsurface sand filter beds and trenches(a) General. Subsurface sand filters without underdrains shall meet the following criteria: (1) Subsurface sand filters may not be utilized on soils where the limiting zone occurs at less than 6 feet below the mineral soil surface.(2) The average percolation rate, as determined by § 73.15 (relating to percolation tests), shall be greater than 90 minutes per inch.(3) The average percolation rate at a depth between 36 and 60 inches shall be within the range of 3-90 minutes per inch.(4) The average percolation rate obtained from paragraph (3) shall be applied to § 73.16(c) (relating to absorption area requirements) for determination of the absorption area and other system requirements.(5) System design shall meet the requirements of § 73.52 (relating to standard trenches) or § 73.53 (relating to seepage beds) except as modified by subsection (b).(b)Construction. Subsurface sand filters shall be constructed as follows: (1) The maximum depth of the excavation shall be 5 feet.(2) Sand meeting the specifications of § 73.55(c) (relating to sand specifications) shall be placed in the entire bed or trench to a minimum depth of 12 inches.The provisions of this § 73.54 adopted January 21, 1983, effective 1/22/1983, 13 Pa.B. 508; amended November 7, 1997, effective 11/8/1997, 27 Pa.B. 5877.The provisions of this § 73.54 amended under section 9 of the Pennsylvania Sewage Facilities Act (35 P. S. § 750.9); The Clean Streams Law (35 P. S. §§ 691.1-691.1001); and section 1920-A of The Administrative Code of 1929 (71 P. S. § 510-20).
This section cited in 25 Pa. Code § 71.63 (relating to retaining tanks).